Shears



No. 6I3,873. Patented Nov. 8, I898. A. ZINSGBAF.

S H E A R 8.

(Application filed N 011. 22, 1897,)

(No Model.)

Y Q mm UNITED STATES PATENT OFFICE.

AUGUST ZINSGRAF, or Los ANGELES, CALIFORNIA.

SHEARS.

SPECIFICATION forming part of Letters Patent No. 313,873, dated November8, 1898.

' Application filed November 22, 1897. Serial No. 659,516. (No model.)

To all whom it may concern.-

Be it known that I, AUGUST ZINSGRAF, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have invented new and useful Improvements in Shears, ofwhich the following is a specification.

My invention relates to that class of shears in which an archedspring-bar is applied on the outside of one of the blades and by whichpressure is applied through the shears-pivot to yieldingly hold theedges of the shears together in making the cut.

An object of my invention is to provide simpler and better means foraccomplishing the purpose than has heretofore been provided.

One object which I have in view is to provide very simple and practicalmeans for adj usting the pressure of the spring to hold the edges of theblades in proper contact while the cutting is being done and to leavethe blades entirely free when the shears are open, so as to avoid anyunnecessary expenditure of force in operating the shears. In this regardan object of my invention is to apply the blade-holding pressure as nearthe midline of the blade as possible, as distinguished from applyingsuch pressure at the sides or at either side of the mid-line of theblade, thus to allow the blades to readily adjust themselves with theircutting edges in the best position for cutting. By my construction thefront end of the spring presses the blade at a point on the mid-line ofthe blade in front of the pivot and the head of the pivot presses on thespring close to the body of the pivot only, as shown in Figure 2, sothat the blade, which is curved, as usual with shear-blades, will adjustitself to contact with the other blade at a point on the edge and atanother point behind the pivot, and will thus contact with changingpoints during the entire stroke of the blades in closing and openmg.

Another object is to provide for the use of a screw-threaded pivot toscrew into theunder blade and to so arrange the parts that said screwwill not unscrew after it has been set, but will hold its set positionwithout the use of a set-nut until the shears become dull and have to beresharpened. My shears are so made that when the grinder has groundelevation showing my invention.

them upon the inner faces he can readily adjust them to the exacttension necessary for holding the cutting edges together for cuttingwith the greatest ease.

My invention is especially desirable for barbers shears, as by means ofit the grinder can accurately set the blades so that they will outperfectly, although when the blades are fully open they are notspring-pressed, but the blades play loosely and freely, and after theyhtIG become dull and need regrinding they can, after being ground, againbe set accurately, the construction being such as to allow for taking upthe space which is made by frequent grinding. It is to be understoodthat the adjustment of the cutting edges of the shears is a verydelicate proposition and that the size of some of the important featuresis practically microscopic.

An object of my invention is to provide for the use of a very strong,stiff, but not unwieldy spring which will not be liable todeterioration, but will last without weakening or losing its efficiencyso long as the shears last. I place the pivot-hole through the curve orarch at one end of the spring and extend the main body of the springrearward in a straight bar for a considerable distance and to its end,so that the resiliency of the spring is afiorded by the main part of thebody of the bar but the force of the spring is applied to the pivotclose to the fulcrum by the curved portion of the arched end, andalthough the resiliency of the spring is a positive quality it isimpossible to destroy or weaken this resiliency, regardless of thefrequent or severe use to which it may be put.

The accompanying drawings illustrate my invention, some of the viewsbeing enlarged very materially in order to illustrate the invention.

Fig. 1 is a plan of my newly-invented shears closed. Fig. 2 is an edgeelevation of the same. Fig. 3 is a fragmcntal enlarged side Fig. 4 is alongitudinal mid-section of Fig. 3, cutting axially through the pivot.Fig. 5 is a side elevation of the parts shown in Fig. 3 with the shearsopen and supported by the under blade. Figs. 1, 2, and 3, looking to theright. Fig. 7 is a cross-section on line 7 7, Figs. 1, 2, and

Fig. 6 is across-section on line 6 6,

.5, looking to the right. Fig. 8 is a crosssection on line 8 8, Figs. 1,2, and 3, looking to the left.

A indicates the under shears or scissors blade, with screw-threaded holea to receive and hold the pivot.

A is the upper blade, provided with the ordinary plain outer face athrough which is made a smooth circular pivot-hole a, to fit the pivot.

Bis a stiff strong spring-bar straight at its rear end and throughoutits greater length, and having its front end I) rounded and curved toform an arch 1) near the rounded end and provided with a pivot-hole bthroughthe arch and slightly larger than the pivot-hole ct of the upperblade A. Suitable means, such as the screw 0, passing through a slot 1in the rear end of the spring-bar and screwed into the upper blade A, isprovided for fastening the rear end of the bar to the blade behind thepivot.

D is a pivot screw-threaded, as at CZ, at one end and inserted throughthe hole I)" in the bar and through the pivot-hole a in the upper bladeand screwed into the screw-threaded hole a in the lower blade andprovided with a head (1, having a beveled or cone-shaped bearing-face claround the stem of the pivot to bear on the crown of the arch of thespringbar. The efiect of the slant of the front end of the spring-bar isto cause the lower edge of the rounded point or front end of thespringbar to rest on the mid-line of the blade, as on a point formed bythe tip of the spring-bar, so that the front end of the bar is capableof tilting laterally, and the loose fit of the pivot in the hole Z)allows a slight lateral tilting of the spring-bar, so that the pivotwhen screwed down into place to rest on the bar will adjust itself veryaccurately to the bevel of the head, so that there will be only twoslight bearingpoints of the pivot-head on the spring on the oppositesides of the stem of the pivot, such bearing-points being where thebevel of the pivot rests upon the crown of the arch, and the bearing ofthe front end of the spring will remain constant at one point of theblade, so that the blade will not be tilted thereby, but will apply thepressure constantly to hold the blade edges together as the blades areopened and closed. By this means the friction upon the pivot-screw toturn it is practically ml and is much less than the friction required toturn the screw in the screw-threaded hole of the blade,so that themovement of the shear-blades does not tend to unscrew the screw. hen theblades are opened fully, the parts are perfectly loose and free, asindicated in Fig. 5.

The spring-bar is of such construction that 66 it is never bent out ofshape, but always remains in the arched form, the long straight portionof the bar being depended upon for the required resiliency.

Now, having described my invention,what I claim as new, and desire tosecure by Letters Patent, is-

1. The combination of a shears, or scissors blade with screw-threadedhole to receive the screw-threaded end of a pivot; a shears, orscissors, blade provided with a smooth circular hole to loosely fit thepivot; a stiff strong spring-bar straight at one end and througln outits greater length, and having its other end provided with a roundedpoint and being curved to form an arch near the rounded point and tobring the lower edges of such point and the straight end of the springto bear on the blade, and said spring being provided through said curvewith a pivot hole slightly larger than the pivot-hole of the blade;means for fastening the rear end of the bar to the blade behind thepivot; and a pivot, screw-threaded at one end and inserted through thehole in the bar and through the smooth pivot-hole in the blade and beingloose in said hole, and screwed into the screw-threaded hole in theother blade and provided with a head having a beveled bearing-facearound the stem to bear on the crown of the arch of the springbarsubstantially as set forth.

2. The combination with the shears-blade of the arched spring, havingthe rounded point at the front end and being straight throughout itsrear portion and main length and bearing upon the shears-blade at thelower edge of the rounded point and rear end; and a pivot passingthrough the curve of the spring and through one of the shearsblades andscrewed into the other shears-blade and having its head slightly beveledaround its stem to rest upon the crown of the arch of the spring-bar,substantially as set forth.

3. In a shears or scissors an arched spring with rear end fastened tothe blade and with front end bearing at a single point on the blade atthe mid-line thereof, and a pivot with tapering head and passed throughthe arch and the upper blade and screwed into the lower blade, with thetaper-head in contact with the crown of the arch substantially as setforth.

AUGUST ZINSGRAF. \Vitnesses:

JAMES R. Townsnlvn, F. M. TOWNSEND.

